How do I edit /etc/sudoers from a script?

Old thread, but what about:

echo 'foobar ALL=(ALL:ALL) ALL' | sudo EDITOR='tee -a' visudo

Use visudo for this with a custom editor. This solves all the race conditions and "hack" problems with Brian's solution.

#!/bin/shif [ -z "$1" ]; then  echo "Starting up visudo with this script as first parameter"  export EDITOR=$0 && sudo -E visudoelse  echo "Changing sudoers"  echo "# Dummy change to sudoers" >> $1fi

This script will add the line "# Dummy change to sudoers" to the end of sudoers. No hacks and no race conditions.

Annotated version that explains how this actually works:

if [ -z "$1" ]; then  # When you run the script, you will run this block since $1 is empty.  echo "Starting up visudo with this script as first parameter"  # We first set this script as the EDITOR and then starts visudo.  # Visudo will now start and use THIS SCRIPT as its editor  export EDITOR=$0 && sudo -E visudoelse  # When visudo starts this script, it will provide the name of the sudoers   # file as the first parameter and $1 will be non-empty. Because of that,   # visudo will run this block.  echo "Changing sudoers"  # We change the sudoers file and then exit    echo "# Dummy change to sudoers" >> $1fi

You should make your edits to a temporary file, then use visudo -c -f sudoers.temp to confirm that the changes are valid and then copy it over the top of /etc/sudoers

#!/bin/shif [ -f "/etc/sudoers.tmp" ]; then    exit 1fitouch /etc/sudoers.tmpedit_sudoers /tmp/sudoers.newvisudo -c -f /tmp/sudoers.newif [ "$?" -eq "0" ]; then    cp /tmp/sudoers.new /etc/sudoersfirm /etc/sudoers.tmp